1. Field of the System
This system relates to the field of fluid pressure-driven mechanisms.
2. Background Art
There are a number of situations and circumstances which require the locking of an apparatus against movement until the occurrence of an anticipated event or the presentation of a certain condition for which the apparatus is intended and in which there is an available source of force (for example, atmospheric or hydrostatic pressure) which may be employed to unlock and actuate the apparatus. For example, it may be necessary to lock a triggering mechanism in an automatic flotation device, or in an automatic release mechanism for lifeboats, liferafts, or emergency position indicating radio beacons, against inadvertent actuation due to shock or vibration while not in the water until the device is immersed in water, or until it is immersed to an intended depth, or until a triggering event or circumstance has occurred. Similarly, it may be necessary to lock a triggering mechanism in an automatic parachute opening device against inadvertent actuation due to shock or vibration until the device reaches an intended altitude, or until a triggering event or circumstance has occurred. Such locking may be provided by the presence of a mechanical block against movement of an actuating member of such triggering mechanisms. Such a mechanical block must be subsequently removed to enable actuation of such triggering mechanisms.